A nonsense book with a very real idea back of it- the idea that mind is man's most potent tool. Pers Crowell has shown a sound appreciation of some of the phases a child goes through, with imagination running riot with odd combinations of familiar things and made-up words that link sound patterns. With amusing pictures in bold line and wash, the gifted author-illustrator introduces basic concepts of thought processes,- memory, imagination, abstractions, deductions. Games are suggested to use these faculties as a playing field of invention. And in a parable he indicates that posing a problem and working out a solution can lead to something practical. A very original book, which should appeal to unusual children.